1. Field of the Invention
The present invention relates to a dual type flat panel display device, and more specifically, a dual type flat panel display device and a portable display apparatus using the same, which includes an integrated flexible printed circuit board transferring electrical signals to the flat panel display panel and a light source device mounted in the flat panel display as a backlight unit
2. Description of the Related Art
In the contemporary terminology, a dual type flat panel display device means a flat panel display device including two display panels that display images in opposite directions. The two display panels are usually configured of a main display panel and a sub-display panel. For example, a main display panel is configured of a liquid crystal display device and a sub-display panel is configured of a liquid crystal display device or an organic electro-luminescence display device.
A dual type flat panel display device includes a printed circuit board for driving a main display panel, a first flexible printed circuit board for transferring signals form the printed circuit board to the main display panel to drive the main display panel, and a second flexible printed circuit board transferring signals form the printed circuit board to a sub-display panel to drive the sub-display panel
A flexible printed circuit board (FPCB) is a type of a printed circuit board having flexibility. The flexible printed circuit board has a conductive thin film layer such as copper formed in a pattern on a base film of an insulated resin material, and has a protective film formed on the thin film layer. FIG. 1 is a cross-sectional view of a flexible printed circuit board. The flexible printed circuit board is disclosed in Korean Patent Laid-Open Publication No. 10-2005-0064550. According to the disclosure, the flexible printed circuit board is formed with conductive wiring layer 12 and protective film 30 covering wiring layer 12. A part of conductive wiring layer 12 is exposed without protective film 30 (portion a in FIG. 1) for a connection to a terminal of an external device. Conductive wiring layer 12 with a circuit pattern is formed on base film 11.
A dual type flat panel display device has an additional flexible printed circuit board in addition to the first and second flexible circuit board described above. The additional flexible printed circuit board is necessary to connect the printed circuit board to a light source device to provide necessary electrical energy to the light source device. The increased number of flexible printed circuit board, however, makes the structure of portable display apparatus complicated.